# Systematic Review Report: [Review title]

> Report template for a completed systematic review, with or without
> meta-analysis. The sections follow the topics and order of the PRISMA
> 2020 statement (27 items, published in BMJ 2021;372:n71), including the
> flow diagram, risk-of-bias tables and a GRADE summary of findings.
> PRISMA item numbers appear in brackets, for example [16a], so you can
> fill the official checklist quickly. Topics are written in original
> words; use the template with the official PRISMA 2020 checklist,
> abstract checklist and flow diagram from prisma-statement.org. This is
> a reporting format, not medical, statistical or methodological advice.
> Replace every `[bracketed]` value and every row marked *Example*.

<!--
Guidance: How to use this template
- Start from your registered protocol (see science/systematic-review).
  Report what was done, and list every difference from the protocol in
  section 4.11 with a reason.
- Fill the flow diagram counts (section 5.1) first. Every later number
  (studies, participants, studies per analysis) must reconcile with them.
- Keep the bracketed PRISMA 2020 item numbers. The cross-reference table
  in section 8.1 maps each item to a section of this report.
- Rows marked *Example* describe a fictional review of supervised
  exercise therapy for chronic low back pain by the fictional Northbridge
  Evidence Synthesis Unit, the same example used in the protocol
  template. All study IDs (ST-01 to ST-14) and numbers are invented and
  were computed so that they add up. Delete them when you fill your own.
- Never include identifying participant data. Individual participant data
  reviews have extra duties under data protection law and data sharing
  agreements.
-->

## Document control

<!-- Guidance: Treat the manuscript as a controlled document. The version reported here must match the version submitted to the journal and the registry record. -->

| Field | Value |
|---|---|
| Document ID | [SRR-001] |
| Review title | [Full title as registered] |
| Registration | [PROSPERO CRD number / OSF Registries DOI] |
| Protocol version reported against | [Protocol v1.2, YYYY-MM-DD] |
| Review type | [Systematic review with meta-analysis / without meta-analysis / update of an earlier review] |
| Reporting guideline | PRISMA 2020 [plus extensions used, for example PRISMA-S for searches, SWiM, PRISMA-NMA] |
| Date of last search | YYYY-MM-DD |
| Version | [0.1] |
| Status | [Draft / In review / Approved] |
| Owner | [@lead-reviewer] |
| Approvers | [@second-reviewer], [@statistician], [@information-specialist] |
| Last updated | YYYY-MM-DD |
| Classification | [Confidential until publication] |

### Approvals

| Role | Name | Decision | Date |
|---|---|---|---|
| Lead reviewer | [@name] | [Approved] | YYYY-MM-DD |
| Statistician | [@name] | [Approved] | YYYY-MM-DD |
| Information specialist | [@name] | [Approved] | YYYY-MM-DD |
| Content expert or guarantor | [@name] | [Approved] | YYYY-MM-DD |

### Revision history

| Version | Date | Author | Change summary |
|---|---|---|---|
| 0.1 | YYYY-MM-DD | [@name] | First full draft after synthesis |
| 0.2 | YYYY-MM-DD | [@name] | *Example:* Search rerun before submission; one new trial screened and excluded |
| 1.0 | YYYY-MM-DD | [@name] | Approved for journal submission |

## Contents

<!-- Guidance: Keep the numbering in step with the headings. PRISMA does not require this order for a journal article, but following it makes the checklist easy to complete. -->

1. [Title and abstract](#1-title-and-abstract)
2. [Introduction](#2-introduction)
3. [Registration, support and availability](#3-registration-support-and-availability)
4. [Methods](#4-methods)
5. [Results](#5-results)
6. [Discussion](#6-discussion)
7. [Summary of findings](#7-summary-of-findings)
8. [PRISMA cross-reference, glossary and references](#8-prisma-cross-reference-glossary-and-references)

## 1. Title and abstract

<!-- Guidance: The title must say "systematic review" (and "meta-analysis" if one was done). Write the abstract last, against the separate PRISMA 2020 for Abstracts checklist, and check that every number in it appears in the results. -->

The title and abstract let readers find the review and judge it quickly.

### 1.1 Title [1]

**[Intervention] for [condition] in [population]: a systematic review
[and meta-analysis]**

*Example:* "Supervised exercise therapy for chronic low back pain in
adults: a systematic review and meta-analysis of randomised trials."

### 1.2 Structured abstract [2]

| Heading | Content |
|---|---|
| Objectives | [Main question in one sentence] |
| Eligibility criteria | [Population, intervention, comparator, outcomes, designs] |
| Information sources | [Databases and registers, date of last search] |
| Risk of bias | [Tool used, for example RoB 2] |
| Synthesis | [Model, effect measure] |
| Results | *Example:* 14 randomised trials (2,442 participants). Pain at about 12 weeks: mean difference -1.17 points on a 0 to 10 scale (95% CI -1.55 to -0.78; 12 trials, 2,172 participants; low certainty). Adverse events: risk ratio 1.45 (1.07 to 1.96; 8 trials; low certainty). |
| Limitations | [Main limitations of the evidence and of the review process] |
| Interpretation | [One balanced sentence] |
| Funding and registration | [Funder; registration number] |

## 2. Introduction

<!-- Guidance: Explain what is already known and why this review was needed now. If earlier reviews exist, say how this one differs (newer trials, better methods, a different question). -->

The introduction states the problem, the gap and the exact questions.

### 2.1 Rationale [3]

[Describe the condition, its burden and current practice. Summarise
earlier reviews and explain the uncertainty this review resolves.]

*Example:* The most recent review of exercise for chronic low back pain
searched to 2017 and did not assess risk of bias with RoB 2. Several
large trials have been published since.

### 2.2 Objectives [4]

| ID | Objective |
|---|---|
| OBJ-01 *(Example)* | Estimate the effect of supervised exercise therapy compared with usual care or no treatment on pain intensity at about 12 weeks in adults with chronic low back pain |
| OBJ-02 *(Example)* | Estimate the effect on the risk of adverse events |
| OBJ-03 | [Further objective, for example function or return to work] |

## 3. Registration, support and availability

<!-- Guidance: PRISMA 2020 places these items under "Other information" at the end. Many journals print them in the front or back matter; fill them here once and copy them where the journal wants them. -->

These items let readers compare the review with its plan and find the
underlying data and code.

### 3.1 Registration and protocol [24a, 24b, 24c]

| Item | Detail |
|---|---|
| Registry and number [24a] | [PROSPERO CRD number / OSF DOI], registered YYYY-MM-DD |
| Where the protocol can be found [24b] | [Registry record, journal reference or repository link] |
| Amendments to registration or protocol [24c] | See section 4.11 |

### 3.2 Support and competing interests [25, 26]

| Item | Detail |
|---|---|
| Funding and other support [25] | [Funder, grant number] |
| Role of funders [25] | *Example:* The funder had no role in design, conduct, analysis, interpretation or the decision to publish |
| Competing interests [26] | [Declarations per author. Name any reviewer who authored an included study and how that study was handled.] |

### 3.3 Availability of data, code and other materials [27]

| Material | Available? | Where |
|---|---|---|
| Data extraction forms | [Yes / No] | [Repository link] |
| Extracted data | *Example:* Yes | [Repository DOI] |
| Analysis code | *Example:* Yes | [Code repository, tagged release] |
| Full search strategies | Yes | Appendix A |
| Risk-of-bias judgements with support | [Yes] | Appendix C |

## 4. Methods

<!-- Guidance: Describe what you actually did with enough detail for another team to repeat it. Point to the protocol for detail, but report every change. -->

The methods follow the order of the PRISMA 2020 methods items.

### 4.1 Eligibility criteria [5]

<!-- Guidance: State the criteria for studies and for reports, and say how studies were grouped for each synthesis. -->

| Element | Criterion |
|---|---|
| Population | *Example:* Adults aged 18 or over with low back pain lasting 12 weeks or more |
| Intervention | *Example:* Exercise therapy supervised by a health professional |
| Comparator | *Example:* Usual care, waiting list or no treatment |
| Outcomes | *Example:* Pain intensity (primary), function, adverse events |
| Study design | *Example:* Randomised controlled trials |
| Report characteristics | [Years, languages, publication status, registry results included] |
| Grouping for synthesis | [For example by comparator type: usual care versus no treatment] |

### 4.2 Information sources [6]

| Source | Platform or URL | Date last searched |
|---|---|---|
| MEDLINE | [Ovid] | YYYY-MM-DD |
| Embase | [Ovid / Elsevier] | YYYY-MM-DD |
| CENTRAL | [Cochrane Library] | YYYY-MM-DD |
| Trial registries | [ClinicalTrials.gov, WHO ICTRP] | YYYY-MM-DD |
| Other methods | [Reference lists, citation searching, contact with authors] | YYYY-MM-DD |

### 4.3 Search strategy [7]

[State that full strategies for every database, register and website,
with filters and limits, appear in appendix A. Name who designed and who
peer reviewed the search, for example with the PRESS checklist.]

### 4.4 Selection process [8]

[Number of reviewers who screened each record and each report, whether
they worked independently, how disagreements were resolved, and any
automation tool used, with how it was used and validated.]

### 4.5 Data collection process [9]

[Number of reviewers who extracted data, independence, how missing data
were obtained from investigators, and any automation tool.]

### 4.6 Data items [10a, 10b]

<!-- Guidance: List every outcome sought, the time points and the rule used when a study reported several results for the same outcome. Then list the other variables (participant, intervention and funding characteristics). -->

| ID | Outcome | Measures accepted | Time point and selection rule |
|---|---|---|---|
| OUT-01 *(Example)* | Pain intensity | Any validated 0 to 10 or 0 to 100 scale, converted to 0 to 10 | Closest to 12 weeks within 6 to 26 weeks |
| OUT-02 | [Function] | [Instruments] | [Time point] |
| OUT-03 *(Example)* | Adverse events | Participants with any adverse event | End of intervention |

**Other variables [10b]:** [age, sex, symptom duration, intervention
dose and provider, comparator detail, setting, funding source]. State
any assumptions made about missing or unclear information.

### 4.7 Study risk of bias assessment [11]

[Tool and version, for example RoB 2 (version of 22 August 2019) for
randomised trials, assessed per outcome; number of assessors and
independence; how overall judgements were reached.]

### 4.8 Effect measures [12]

| Outcome type | Effect measure |
|---|---|
| Continuous, same scale | Mean difference (MD) |
| Continuous, different scales | [Standardised mean difference (SMD), Hedges' g] |
| Binary | [Risk ratio (RR), with absolute risk difference for the summary of findings] |

### 4.9 Synthesis methods [13a to 13f]

<!-- Guidance: Report each of the six sub-items: which studies went into each synthesis, data preparation, tabulation and display, the statistical model, exploration of heterogeneity, and sensitivity analyses. -->

| Sub-item | Method |
|---|---|
| Eligibility for each synthesis [13a] | *Example:* All trials with usable pain data at 6 to 26 weeks |
| Data preparation [13b] | [Conversion of scales, imputation of missing SDs, handling of multi-arm trials] |
| Tabulation and display [13c] | [Forest plots, characteristics tables] |
| Model and software [13d] | *Example:* Random-effects, REML estimate of $\tau^2$, Hartung-Knapp-Sidik-Jonkman confidence interval; [software and version] |
| Heterogeneity [13e] | [$I^2$, $\tau^2$, prediction interval; prespecified subgroups] |
| Sensitivity analyses [13f] | [Excluding high risk of bias; alternative model] |

Heterogeneity is summarised with Cochran's $Q$ and

$$
I^2 = \max\left(0,\ \frac{Q - df}{Q}\right) \times 100\%
$$

with $df = k - 1$ for $k$ studies.

### 4.10 Reporting bias and certainty assessment [14, 15]

[Methods for assessing missing results (for example comparison with
registry records, funnel plots and Egger's test when 10 or more studies
contribute) and for rating certainty of evidence per outcome (for example
GRADE, using the Core GRADE guidance).]

### 4.11 Differences from the protocol

<!-- Guidance: PRISMA 2020 asks for amendments under item 24c. List every change, its date and whether it was made before or after results were known. -->

| ID | Change | Date | Reason | Before results known? |
|---|---|---|---|---|
| DEV-01 *(Example)* | Added a regional database | YYYY-MM-DD | Search peer review found trials indexed only there | Yes |
| DEV-02 *(Example)* | Used REML instead of DerSimonian-Laird | YYYY-MM-DD | Methods guidance updated; prespecified in the analysis plan | Yes |

## 5. Results

<!-- Guidance: Present results in the order of the outcomes in section 4.6. Every count must reconcile with the flow diagram. -->

This section reports what was found and how much confidence it deserves.

### 5.1 Study selection [16a, 16b]

<!-- Guidance: The diagram mirrors the PRISMA 2020 flow diagram for new reviews with a separate "other methods" column. Replace this sketch with the official template in the final manuscript. Cite each study excluded at full text that readers might expect to see included, with the reason [16b]. -->

The flow diagram traces records from identification to inclusion.

```mermaid
flowchart TD
    A["Records from databases (n = 1,842) and registers (n = 214)"] --> B["Duplicates removed before screening (n = 618)"]
    A --> C["Records screened (n = 1,438)"]
    C --> D["Records excluded (n = 1,312)"]
    C --> E["Reports sought for retrieval (n = 126)"]
    E --> F["Reports not retrieved (n = 4)"]
    E --> G["Reports assessed for eligibility (n = 122)"]
    G --> H["Reports excluded (n = 109)"]
    G --> I["Studies included (n = 14), reports (n = 15)"]
    J["Records from citation searching (n = 23)"] --> K["Reports assessed for eligibility (n = 22), not retrieved (n = 1)"]
    K --> L["Reports excluded (n = 20)"]
    K --> I
```

| Stage | Databases and registers | Other methods |
|---|---|---|
| Records identified | *Example:* 2,056 (1,842 + 214) | 23 |
| Duplicates removed | 618 | Not applicable |
| Records screened | 1,438 | 23 |
| Records excluded at title and abstract | 1,312 | 0 |
| Reports sought / not retrieved | 126 / 4 | 23 / 1 |
| Reports assessed | 122 | 22 |
| Reports excluded | 109 | 20 |
| Reports included | 13 (12 studies) | 2 (2 studies) |

*Example:* reports excluded at full text, with reasons: wrong population
38, wrong intervention 29, wrong comparator 17, not randomised 20, no
usable outcome data 5 (total 109). Reports excluded from other methods:
not randomised 12, wrong intervention 8 (total 20). The list of excluded
reports with reasons is in appendix B.

### 5.2 Study characteristics [17]

<!-- Guidance: One row per included study. Cite each study. Keep the full table in a supplement if it is long. -->

| Study | Country | n (int / ctl) | Intervention | Comparator | Pain measure | Follow-up |
|---|---|---|---|---|---|---|
| ST-01 *(Example)* | [Country] | 60 / 58 | Group exercise, 8 weeks | Usual care | NRS 0 to 10 | 12 weeks |
| ST-04 *(Example)* | [Country] | 200 / 196 | Individual physiotherapy exercise, 12 weeks | Usual care | VAS 0 to 100 | 12 weeks |
| ST-13 *(Example)* | [Country] | 80 / 78 | Pilates, 10 weeks | Waiting list | Not usable (median only, no spread) | 10 weeks |
| [ST-nn] | [Country] | [n / n] | [Intervention] | [Comparator] | [Measure] | [Time] |

*Example:* 14 trials randomised 2,442 participants. Twelve trials (1,090
intervention, 1,082 comparator, 2,172 in total) reported usable pain
data; ST-13 and ST-14 (270 participants) did not.

### 5.3 Risk of bias in studies [18]

<!-- Guidance: Give the judgement for each domain and overall, per outcome. A traffic-light table is standard. Do not average domain judgements: the overall judgement follows the tool's rules. -->

RoB 2 domains: D1 randomisation process, D2 deviations from intended
interventions, D3 missing outcome data, D4 measurement of the outcome,
D5 selection of the reported result. Judgements: Low, Some concerns,
High. Outcome assessed: pain intensity (OUT-01).

| Study | D1 | D2 | D3 | D4 | D5 | Overall |
|---|---|---|---|---|---|---|
| ST-01 *(Example)* | Low | Low | Low | Some concerns | Low | Some concerns |
| ST-02 | Low | Low | Low | Low | Low | Low |
| ST-03 | Some concerns | Low | High | Some concerns | Low | High |
| ST-04 | Low | Low | Low | Low | Low | Low |
| ST-05 | High | Low | Some concerns | Some concerns | Low | High |
| ST-06 | Low | Low | Low | Some concerns | Low | Some concerns |
| ST-07 | Low | Low | Low | Low | Low | Low |
| ST-08 | Low | Some concerns | Low | Some concerns | Low | Some concerns |
| ST-09 | Low | Low | Low | Some concerns | Low | Some concerns |
| ST-10 | Low | Low | Low | Some concerns | Low | Some concerns |
| ST-11 | Some concerns | Low | Low | Some concerns | High | High |
| ST-12 | Low | Low | Low | Low | Low | Low |

*Example:* 4 trials at low risk, 5 with some concerns and 3 at high
risk of bias for pain. The common concern (D4) was self-reported pain by
participants who knew their allocation.

### 5.4 Results of individual studies [19]

<!-- Guidance: For every study in every synthesis, give summary data per group (or the effect estimate and its precision). A forest plot meets this item when it shows these values. -->

| Study | MD (95% CI), 0 to 10 scale | Weight (%) | Overall risk of bias |
|---|---|---|---|
| ST-01 *(Example)* | -1.60 (-2.42 to -0.78) | 7.5 | Some concerns |
| ST-02 | -0.90 (-1.45 to -0.35) | 10.0 | Low |
| ST-03 | -2.10 (-3.18 to -1.02) | 5.7 | High |
| ST-04 | -0.60 (-0.99 to -0.21) | 11.5 | Low |
| ST-05 | -1.90 (-3.08 to -0.72) | 5.1 | High |
| ST-06 | -1.20 (-1.89 to -0.51) | 8.7 | Some concerns |
| ST-07 | -0.40 (-0.89 to 0.09) | 10.6 | Low |
| ST-08 | -1.50 (-2.44 to -0.56) | 6.6 | Some concerns |
| ST-09 | -0.80 (-1.54 to -0.06) | 8.2 | Some concerns |
| ST-10 | -1.40 (-1.99 to -0.81) | 9.6 | Some concerns |
| ST-11 | -2.40 (-3.38 to -1.42) | 6.3 | High |
| ST-12 | -0.70 (-1.23 to -0.17) | 10.2 | Low |
| **Pooled (random effects)** | **-1.17 (-1.55 to -0.78)** | **100.0** | |

### 5.5 Results of syntheses [20a to 20d]

<!-- Guidance: For each synthesis, briefly summarise the characteristics and risk of bias of the contributing studies [20a], then give the pooled estimate with its confidence interval and heterogeneity [20b], the results of heterogeneity exploration [20c] and of sensitivity analyses [20d]. -->

| ID | Outcome | Studies (participants) | Effect (95% CI) | Heterogeneity | Item |
|---|---|---|---|---|---|
| SYN-01 *(Example)* | Pain at about 12 weeks | 12 (2,172) | MD -1.17 (-1.55 to -0.78) | $I^2$ = 64%, $\tau^2$ = 0.22, prediction interval -2.28 to -0.05 | 20b |
| SYN-02 *(Example)* | Adverse events | 8 (1,773) | RR 1.45 (1.07 to 1.96), Mantel-Haenszel | [Report $I^2$] | 20b |
| SEN-01 *(Example)* | Pain, excluding high risk of bias | 9 (1,875) | MD -0.92 (-1.24 to -0.61) | $I^2$ = 45% | 20d |
| SUB-01 | [Subgroup by comparator type] | [k (n)] | [Effect] | [Test for subgroup differences] | 20c |

*Example:* for SYN-01, $Q = 30.64$ with $df = 11$, so
$I^2 = (30.64 - 11) / 30.64 = 64.1\%$. All 12 point estimates favoured
exercise and the prediction interval excludes zero, so the direction of
effect is consistent even though its size varies. Removing the three
high-risk trials shrank the effect to -0.92 points, which suggests that
part of the pooled effect comes from trials with weaker methods.

### 5.6 Reporting biases [21]

*Example:* The funnel plot for pain (12 trials) was asymmetric, with
smaller trials showing larger effects. Egger's regression intercept was
-4.32 (standard error 0.82, $t = -5.28$, 10 degrees of freedom,
$P < 0.001$). Two registered trials (registered YYYY and YYYY) have no
published results; their investigators did not reply to two requests.

### 5.7 Certainty of evidence [22]

[Report the certainty per outcome and the reasons for each rating. The
full summary of findings is in section 7.]

## 6. Discussion

<!-- Guidance: Interpret the results in the light of other evidence, separate the limitations of the evidence from the limitations of the review process, and draw implications that match the certainty ratings. -->

The discussion interprets the findings honestly and says what they mean
for practice, policy and future research.

### 6.1 General interpretation [23a]

[Compare the results with other reviews and guidelines. Relate the effect
size to the minimal important difference, for example 1 point on a 0 to
10 pain scale, and state whether the confidence interval includes it.]

### 6.2 Limitations of the evidence [23b]

- [Risk of bias: for example self-reported outcomes in unblinded trials]
- [Inconsistency and its possible explanations]
- [Indirectness of populations, interventions or settings]
- [Imprecision and reporting biases]

### 6.3 Limitations of the review process [23c]

- [Language, date or database restrictions]
- [Data obtained by imputation or estimation]
- [Decisions taken after seeing the data, from section 4.11]

### 6.4 Implications [23d]

[Implications for practice, policy and research. Phrase them to match the
certainty: low-certainty evidence supports "may", not "does".]

## 7. Summary of findings

<!-- Guidance: One row per critical or important outcome. Give absolute effects with an assumed comparator risk for binary outcomes, the number of participants and studies, the certainty and the reasons for downgrading or upgrading. -->

Certainty levels: high, moderate, low, very low. Evidence from randomised
trials starts at high and may be rated down for risk of bias,
inconsistency, indirectness, imprecision and publication bias.

| Outcome | Comparator | With exercise | Relative effect (95% CI) | Participants (studies) | Certainty | Reasons |
|---|---|---|---|---|---|---|
| Pain, 0 to 10, about 12 weeks *(Example)* | [Mean in comparator groups] | MD 1.17 points lower (1.55 lower to 0.78 lower) | Not applicable | 2,172 (12 RCTs) | Low | Risk of bias (-1); publication bias (-1) |
| Adverse events *(Example)* | 74 per 1,000 | 107 per 1,000 (33 more, 5 more to 71 more) | RR 1.45 (1.07 to 1.96) | 1,773 (8 RCTs) | Low | Risk of bias, harms not collected systematically (-1); imprecision, few events (-1) |
| [Function] | [Value] | [Value] | [Value] | [n (k)] | [Level] | [Reasons] |

*Example:* the absolute effect for adverse events applies the pooled RR
to the comparator risk: $65 / 882 = 74$ per 1,000, and
$74 \times 1.446 = 107$ per 1,000.

### 7.1 GRADE judgements per domain

| Outcome | Risk of bias | Inconsistency | Indirectness | Imprecision | Publication bias |
|---|---|---|---|---|---|
| Pain *(Example)* | Serious: 3 of 12 trials at high risk; effect smaller without them | Not serious: consistent direction, prediction interval excludes zero | Not serious | Not serious | Strongly suspected: funnel asymmetry, unpublished registered trials |
| Adverse events *(Example)* | Serious: non-systematic collection | Not serious | Not serious | Serious: 160 events in total | Undetected |

## 8. PRISMA cross-reference, glossary and references

<!-- Guidance: Complete the official PRISMA 2020 checklist with the location of each item in the final manuscript and submit it with the review. -->

This section maps the PRISMA 2020 items to this report and lists terms
and sources.

### 8.1 PRISMA 2020 cross-reference

| Item | Topic (paraphrased) | Section |
|---|---|---|
| 1, 2 | Title, abstract | 1.1, 1.2 |
| 3, 4 | Rationale, objectives | 2.1, 2.2 |
| 5 | Eligibility criteria | 4.1 |
| 6, 7 | Information sources, search strategy | 4.2, 4.3 |
| 8, 9 | Selection and data collection processes | 4.4, 4.5 |
| 10a, 10b | Data items | 4.6 |
| 11, 12 | Risk of bias assessment, effect measures | 4.7, 4.8 |
| 13a to 13f | Synthesis methods | 4.9 |
| 14, 15 | Reporting bias and certainty assessment | 4.10 |
| 16a, 16b | Study selection | 5.1 |
| 17, 18, 19 | Study characteristics, risk of bias, individual results | 5.2, 5.3, 5.4 |
| 20a to 20d | Results of syntheses | 5.5 |
| 21, 22 | Reporting biases, certainty of evidence | 5.6, 5.7, 7 |
| 23a to 23d | Discussion | 6 |
| 24a to 24c | Registration and protocol | 3.1, 4.11 |
| 25, 26 | Support, competing interests | 3.2 |
| 27 | Availability of data, code and other materials | 3.3 |

### 8.2 Glossary

| Term | Meaning |
|---|---|
| GRADE | Grading of Recommendations Assessment, Development and Evaluation: a system for rating certainty of evidence |
| HKSJ | Hartung-Knapp-Sidik-Jonkman method for the confidence interval of a random-effects mean |
| MD, SMD, RR | Mean difference, standardised mean difference, risk ratio |
| Prediction interval | Range in which the true effect of a new similar study is expected to lie |
| REML | Restricted maximum likelihood estimator of the between-study variance |
| RoB 2 | Cochrane risk-of-bias tool for randomised trials, version 2 |
| ROBINS-I | Risk Of Bias In Non-randomised Studies of Interventions |

### 8.3 References and related templates

| Reference | Version or date | Use |
|---|---|---|
| PRISMA 2020 statement, Page MJ et al., BMJ 2021;372:n71, https://doi.org/10.1136/bmj.n71 | 2021 | Reporting items and flow diagram |
| PRISMA 2020 explanation and elaboration, BMJ 2021;372:n160, https://doi.org/10.1136/bmj.n160 | 2021 | Detailed guidance per item |
| Official checklists and flow diagrams, https://www.prisma-statement.org/prisma-2020 | Checked 2026-10-30 | Submission files |
| RoB 2, Sterne JAC et al., BMJ 2019;366:l4898, https://doi.org/10.1136/bmj.l4898 | Tool version of 22 August 2019 | Risk of bias in randomised trials |
| ROBINS-I, Sterne JAC et al., BMJ 2016;355:i4919; ROBINS-I V2 at https://www.riskofbias.info | V2 draft posted 20 November 2025 | Risk of bias in non-randomised studies |
| Core GRADE series, BMJ 2025, starting with https://doi.org/10.1136/bmj-2024-081903 | 2025 | Certainty of evidence |
| Cochrane Handbook for Systematic Reviews of Interventions, https://training.cochrane.org/handbook | Version 6.5, 2024 | Methods |
| science/systematic-review | This collection | Protocol written before the review |
| science/scoping-review-protocol | This collection | When the question is about the extent of evidence rather than effects |
| academic/stats-effect-sizes | This collection | Effect measures and conversions |
| academic/research-paper-imrad, academic/peer-review | This collection | Manuscript and peer review |

## Standard and licence note

Based on the PRISMA 2020 statement: Page MJ, McKenzie JE, Bossuyt PM,
Boutron I, Hoffmann TC, Mulrow CD, et al., *The PRISMA 2020 statement:
an updated guideline for reporting systematic reviews*, BMJ
2021;372:n71 (https://doi.org/10.1136/bmj.n71), published open access
under the Creative Commons Attribution licence (CC BY 4.0). This
template follows the order of its 27 items and sub-items, paraphrased in
original text, and reproduces no checklist wording; use the official
checklist, abstract checklist and flow diagram from
https://www.prisma-statement.org for submission. Risk-of-bias domain
names are those of RoB 2 (riskofbias.info), and certainty levels follow
GRADE. Check the current versions of these tools before you start, as
they are updated. This is a reporting format, not medical, statistical
or methodological advice. Template licence: MIT.